A well known refrigeration system includes in closed series-flow relationship, an evaporator, a compressor for withdrawing refrigerant from the evaporator, a condenser for condensing the refrigerant compressed by the compressor and tubular flow restrictor means commonly called a capillary tube for controlling the flow of refrigerant to the evaporator. The capillary tube maintains the desired pressure differential between the condenser and the evaporator by restricting the flow of refrigerant therethrough and to this end its internal diameter is substantially less than the internal diameter of the conduit forming the inlet end of the evaporator. Because of the difference in diameter between the capillary tube and the inlet end of the evaporator, it is common to have a jumper tube that is intermediate and joined to each of the capillary tube and the inlet end of the evaporator to act as a transition section. One of the problems in joining the jumper tube to the capillary tube is that they must be joined without any leaks and because the capillary tube diameter is so small the metal joining operation, such as brazing, must be such that the alloy or flux used in the brazing operation to join the two tubes will not clog the opening of the capillary tube or introduce alloy or flux into the refrigerant system.
The refrigerant exiting from the capillary tube may be in the form of liquid or gas or a mixture of the two. Also, as the refrigerant exits from the capillary tube, a portion of it usually vaporizes at the lower pressure condition in the evaporator. The boiling turbulence resulting from this vaporization as well as the exit velocity of the refrigerant, which is close to sonic speed, constitute a major source of noise in the operation of a refrigeration system. This noise can be quite bothersome in the operation of refrigerant systems such as those contained in refrigerators. Particularly bothersome is the noise generated after the refrigeration system is shut down and the refrigerant system pressure is equalizing. During that time the compressor and fans are off so they do not help mask the noise.
By this invention there is provided a structural arrangement that suppresses the noise created by refrigerant exiting the capillary tube and also the structural arrangement prevents clogging of the outlet end of the capillary tube during the metal joining operation between capillary tube and the jumper tube.